|
Craig Johnson, who runs the website www.ledmuseum.org, where he posts some highly entertaining product reviews, had a few choice words to say about this Chinese-made flashlight advertised as "no battery needed."
"Horse puckey! The LED Survival Light is a plastic flashlight that is supposed to be self-charging (by giving it a shaking or "spanking the monkey" motion), but this shake mechanism is just a phony - the flashlight actually operates from two CR2032 disposable lithium coin cells. The "magnet" inside is just a steel rod, and the two wire leads from the coil are shorted to one another."
Apparently, though, they aren't all bad, as one of Craig's readers reports:
"My light looks exactly like those pictured, right down to the number of bumps on the body, but the magnet actually IS a magnet! I can lift the unit by holding a jeweller's screwdriver above the magnet. The leads from the coil aren't shorted, and are soldered to different connections on the board. I removed the two coin cells and turned the light on, and it works, but the output is very dim. There is a small capacitor on the underside of the board that, I assume, is charged by the magnet/coil. The light was re-assembled and turned on for 42 minutes with no discernable dimming, using the CR2032s, no doubt."
Morale of the story: Buyer Beware, when you're shopping at a dollar store!
Subscribe to this blog's feed
Comments (3)
Hi,
I got one of these for Christmas 2006. It is still going strong except that the on switch needs to be pressed to keep it on. Something must have broken so it won't stay on by itself, even in the on mode.
I have found that it has dimmed and got so bad it was useless. BUT, I spent a few hours shaking it, I know that is a long time and the noise is irritating, but it has come back to life. I also found that when I did shake it, it got brighter when the magnet passed through the middle, for a second of course.
So mine seems to work but only with a lot of effort.
I use it quite often actually.
Paxo
Posted by Ian Paxton | January 16, 2008 1:16 PM
Mine came from a filling station, and looks identical on the outside apart from the rows of bumps but the power definitely comes from the magnet and coil, being stored in a 0.22 Farad (not microfarad!) capacitor on the PCB. The on/off switch has a little magnet on the slider and a reed switch on the PCB. This maintains the integrity of the watertight housing. The operating magnet is actually some small powerful magnets embedded in a larger lump, presumably steel. A nuisance as it drags all the recent UK coinage out of your pocket. I'm sure the unit would be more efficient with metal springs as end stops - the rubber used seems to absorb all the energy. I recently bought a wind-up 3 LED unit which is much brighter and much longer running (and less embarassing to operate).
Posted by John Goldsmith | January 16, 2008 2:05 PM
i have a shake to charge flashlight and it working i have it for 3 years and when i shake it the light is stronger
thank u
Posted by Stav Stef | April 27, 2008 9:46 AM